Traction-engine



P. E. HOLT.

TRACTION ENGINE.V APPLICATION FILED Mme. |914.

Patented July 8, 1919.

2 SHEETS-SHEET l.

INVIGN'IUR j?" Lz/Effaii,

UTN ESSES:

% a@ CZQJ.

P. E. HOLT.

TRACTION ENGINE.

APPLICATION FILED 1AN.6.1914,

1,309,578. Patented July 8, 1919.

2 SHEETS-SHEET 2.

'U rra su Arun Frio.

PLIN'Y E. HOLT, 0F STOCKTON, CALIFORNIA.

i TRACTIoN-ENGINE.

Patented July 8, 1919.

Application filed January 6, 1914. Serial No. 810,671.

1,309,578. Speeicaton of Letters Patent.

To all whom may concern: Be it known that I, PLINY E. Hour, a citizen of the United States, residing at Stockparallelism of the trucks is maintained by the radius rods 13 which are pivoted respectively at their inner ends, as shown at 14,

ton, in the county of San Joaquin and State to the transverse rods or ties of the main 55 of California, have invented new and useframe. The outer ends of the radius 'rods ful Improvements in Traction-Engines, of 13 are pivoted respectively at the points 16 which the following is a specification. to angle brackets 15 mounted on the trian- This invention relates to traction engines gular portions 11 of the trucks and on either of the self-laying track variety and of the s1de of the shaft 9. 17 is a linkv forming 60 type shown in United States Letters Iatent a thrust bar and spacer 'bar which is pivoted #1,026,037, May 14, 1912. at one end as shown at 18 to the main frame The object and advantages of the presadJacent to the drive shaft 4, and the forent invention will be apparent hereinafter. ward end of the link 17 is pivoted at 19 to a The invention consists of the parts and respective truck, and operates to hold the 65 the combination and construction of parts truck properly forward of the sprocket as hereinafter more fully described and wheel 2; it being understood that the truck claimed, having reference to the accompanyis bifurcated to allow the sprocket wheel 2 ing drawings, in whichto revolve. The top plane of the track belt Figure 1 is a side elevation of the Self- 5 is supported between the wheels 2-3 on 70 20 laying track viewed from the right-hand rollers 20 which are journaled on brackets side of the machine, illustrating a part of 21 mounted on a bed plate 22, which in turn the invention. is supported on inverted cross `channels 23. Fig. 2 is a cross section showing the The channels 23 extend across the machine pivoted radius rods for maintaining the and under the side sills A, and form seats 75- 25 alinement of the trucks. for the upper ends of the springs 8. Thus Fig. 3 is a plan view of a fragment of the the entire load of the vehicle is supported running gear. on these channels by the springs 8.

In the present instance I have not-thought The present invention has particularly to it necessary to illustrate the entire traction do with the mounting of the truck 7 and its 80 engine 0r machine, but Simply enough 0f the arrangement with respect to the'rear driving same toshow the essential features of the sprocket 2 and the front idler 3. It has been present invention. customary in the form of engine shown in A represents the main frame 0f the traethe aforementioned Patent, aj-1,026,037, to tion engine; 2 the rear driving sprocket; 3 mount both the wheels 2-3 directly on the 85 the front idler;i4 the drive shaft for the vehicle frame and have them both detached sprocket 2 mounted 0n the main frame of 'XOmthe Spring SllPPOItlg tlllk 7- the vehicle; 5 the endless jointed self-layingI In the present case it is noted that I track passingI around the wheels 2 3 and mount the front idler 3 direct on the truck beneath the track rollers 6 which are 7; thus removing the front idler 3 from the 90 mounted in the truck 7. The load is yieldvehicle frame itself and support it on the ingly supported on the truck and track -hy forward extension on the truck, the truck the springs 8. It is understood that there still remaining independent of the rear. are two of these trucks 7, one on each side drive sprocket 2, The boxes 24 for the of the machine, and they are connected by shaft 25 of the idler 3 are slidably mounted 95 a shaft 9 turning in boxes 10 on the shaft, on guides 26 on vthe truck and adjustment and each truck has a top plate with a properly maintained by the push rods 27 laterally and inwardly projecting triangular adjustable in boxes 28 secured on the top portion 11, which has abox 12 through of the truck 7. By this construction the which box the shaft 9 loosely turns.

The shaft 9 keeps the trucks spaced and upright, while the properalinementand idler 3partakes of all the motions of the truck rlsmg and falling and rocking with it, so that the tendency to back lashand lost .ground run of the track belt.

motion in the flexible tractor 5 is lessened more than where both the front and rear sprockets are independent of the spring truck. The thrust bar 17 maintains the trucks in proper relation to the rear sprocket and enables the truck to rock and yield bodily at all points in its length. Thrust bar 17 Aperforms also another important function in that it allows the endless, selflaying track to contract endwise; that is, for the front sprocket 3 to be drawn toward the rear driving sprocket 4 whenever a rock, or an excess accumulation of sand or gravel or other foreign material gets into the track and between the track and either of the sprockets 2 or 3; the truck and bar 17 under suchconditions and resultant stresses buckling ,downward and forcing the machine frame upward, thereby allowing the obstruction to be cared for without breakage to the machine. Yielding of the truck in this manner is due primarily to the fact that the truck is pivotally connected with the main frame on an axis located at a point beyond all of the rollers, thereby permitting all of the rollers to yield upwardly in unison in a vertical plane. In the present instance the point 18, where the truck is pivotally connected with the main frame, is located in therear of the truck 7 and the rollers 6, so that, when traction conditions require it, the truck may yield upwardly at all points of contact with the The adjustment of the driving sprocket 2 is effected by a push rod 29 seating` against the rear cross channel23.

vAnother reason for mounting thcfront idler 3 on the truck frame rather than on the vehicle frame, is to relieve the vehicle frame of shocks and strains due to the travelof the vehicle over a rough or uneven ground. With the present construction the machine may go into and out of a ditch or down a side hill at an incline, and the track will follow the incline of the ground,

adjusting itself more readily to vany inequalities where the wheel 3 is mounted on the spring truck rather .than where the wheel l3 has a rigid support on the Vehicle frame.

Having thus described my invention what I claim and desire to secure by Letters Patent isl. In a vehicle, the combination of a main frame, aresilient load supporting means for said frame including a roller truck. an endless, flexible track belt supporting said truck, a driving wheel journaled on the main frame and supporting one end of the track belt, an idler journaled on the truck and supporting the other end of the track belt, and pivotal means whereby said roller truck is connected to the main frame at a point beyond all the rollers to permitall of said rollers and vthe idler to yield simultaneously upwardly in a vertical direction.

2. In a vehicle, the combination of a main frame, a resilient load supporting means for said frame including a roller truck, an endless, flexible track belt supporting said truck, a. rear driving wheel journaled on the main frame and supporting the rear end of the track belt, a front idler journaled on the truck and supporting the other end of the track belt, and pivotal means whereby said roller truck is connected to the main frame at a point beyond all the rollers to permit all of said rollers and the idler to yield simultaneously upwardly in a vertical direction.

3. In a vehicle, the combination of a main frame, an endless flexible track belt, a driving wheel journaled in the main frame and supporting one end of the. track belt, a truck having rollers bearing on the ground run of the track belt, an idler journaled on the truck and supporting the other end of the track belt, springs interposed between the truck and frame whereby the frame is yieldingly'supported by the truck` and a link pivote-d at one end to the truck and at its other end to a fixed part of the main frame, whereby all of the rollers and the idler may yield simultaneously upwardly in a vertical plane.

4. In a vehicle, the combination of a main frame, an endless flexible track belt, a rear driving wheel journaled on the frame and supporting the rear end of the track belt, al

truck having rollers bearing on the ground run of the track belt, a front idler journa-led on the truck and; supporting the other end of the track belt, springs interposed between the truck and the main frame whereby the frame is yieldingly supported by.v the truck, and a link connected at one end to the rear end of the truck and pivoted at its other end to a fixed part of the mai-n frame with the axis of oscillation of the truck beyond all of the rollers and idler whereby all of the rollers and idler may yield simultaneously upwardly in a "ertical plane.

5. In a vehicle, the combination of a main frame, a load supporting means for said frame including a roller truck, an endless, flexible track belt supporting said truck, a driving wheel journaled on the main frame and supporting one end of the track belt, an idler liournaled on the truck and supporting the other end of the track belt, and pivotal means whereby said roller truck is connected to the main frame at a point beyond all the rollers to permit all of said rollers and the idler toy yield simultaneously upwardly in a vertical direction.

6. In a vehicle, the combination of a main frame, a load supporting means for said frame, a load supporting means for said frame including a roller truck, springs interposed between the truck and the frame,

an endless flexible track belt supporting said truck, a driving wheel journaled in the main frame and supporting one end of the track belt, an idler journaled on the truck and supporting the other end of the track belt, and pivotal means whereby said roller truck is connected to the main frame at a point beyond all the rollers to permit all of said rollers and the idler to yield simultaneously upwardly in a vertical direction.

8. In a vehicle, the combination of a main frame, a load supporting means for said frame including a roller truck, springs interposed between the truck and the frame, an endless, flexible track belt supporting said truck, a rear driving wheel journaled in the main frame and supporting the rear end of the track belt, a front idler journaled on the truck and supporting the other end of the track belt, and pivotal means whereby said roller truck is connected to the main frame at a point beyond all the rollers to permit all of said rollers and the idler to yield simultaneously upwardly in a vertical direction.

9. In a vehicle, the combination with its frame, of a pair of rotatable driving and supporting Wheels, one of said wheels mounted on the frame, the othermounted on the truck capable of a limited movement ingly supported, said truck capaible of a limited lengthwise movement toward and from the driving sprocket, a front idler sprocket v mounted on the forward end ofl the truck, an endless, flexible track passing around the two sprockets, and means acting normally to maintain the track in alinement and out of interference with the driving sprocket and yet capable of allowing the front sprocket to move toward the rear sprocket and create slack in the chain in the event dirt, stones or other foreign material is carried by the track in the course of its travel around either of said wheels.

11. In a vehicle of the self-laying track variety, the combination of a main frame, a driving sprocket mounted thereon, a spring truck on which the frame is mounted, a front idler sprocket on the truck frame, an endless self-laying track passing around the two sprockets and truck frame, rollers on the truck frame running upon rails of the track, and a push bar member having a fulcrum on the main frame and a pivotal connection with the truck at a point below the horizontal plane of said fulcrum connection with the main frame whereby the push `bar normally maintains the truck in proper position in advance of' the rear sprockets and yet allows the truck and front sprocket to approach the rear sprocket and provide slack in the chain in the event the pitch line of either of said wheels with the chain track is increased.

12. In a vehicle of the self-laying track variety, the combination of a main frame, front and rear sprockets, an endless selflaying track passing around said sprockets, a truck within the endless self-laying track and carrying one of said sprockets, said truck and its said sprocket capable of a limited movement lengthwise of the frame toward the other sprocket, and an'angularly disposed push 'bar having one end pivoted to the main frame and the other end pivoted to the truck, the point of connection of said push barvwith the main frame being above and rearward of the point of connection of the push bar with the truck and between the last-mentioned sprocket and said point of connection of said push bar with the truck, said push bar operating normally to maintain the truck and said sprockets in proper relative position and permitting a limited movement of the truck and its sprocket lengthwise of and relative to the main frame on the lifting of the main frame. 13. In a vehicle, the combination with its frame, of a rear sprocket and a front idler, an endless, flexible track traveling around said rear sprocket and front idler, a roller truck within said track and traveling on the ground run thereof and on which said front idler is mounted, and link connections between the rear end of said truck and the vehicle frame to permit the truck and its front idler to have a limited rearward movement toward In testimony whereof I have hereunto set l the said sprocket Wheel for automatically my hand in the presence of tWo subscribing 10 producing slack in the endless chain track to Witnesses.

permit obstructions, such as dirt stones or i other foreign material, to be carried around PLINY E HOLT' the course of travel of the chain track and Witnesses: between the track and -said sprocket and RUSSELL S. SPRINGER,

front idler. ELLA I. CHISHOLM. 

